The first cases of the 1983 West Bank fainting epidemic begin; Israelis and Palestinians accuse each other of poison gas, but the cause is later determined mostly to be psychosomatic.

The 1983 West Bank fainting epidemic occurred in late March and early April 1983. Researchers point to mass hysteria as the most likely explanation. Large numbers of Palestinians complained of fainting and dizziness, the vast majority of whom were teenage girls with a smaller number of female Israeli soldiers in multiple West Bank towns, leading to 943 hospitalizations.

The cause was determined to be psychological in April 1983, but the fainting spells led to accusations and counter-accusations between Israelis and Palestinians. Israel even arrested some Palestinians during the outbreak, alleging that political agitation was behind the phenomenon. The New York Times reported that "Palestinian leaders have accused Israeli settlers and officials of using 'chemical warfare' in West Bank schools to drive Arabs out of the area" and that some Israeli officials "accused radical Palestinian factions of using gas or chemicals to incite demonstrations."Investigators concluded that the wave of complaints was ultimately a result of mass hysteria, even if some environmental irritant had originally been present. This conclusion was supported by a Palestinian health official, who said that 20% of the early cases may have been caused by the inhalation of some kind of gas, but the remaining 80% were psychosomatic.Albert Hefez was the lead Israeli psychiatric investigator into the incident, and he found that the Israeli press and Palestinian medical personnel both fueled the mass hysteria. He said the Israeli press, by speculating that "poison" was behind the incidents in its early reporting and quoting unnamed Israeli army officials as saying nerve gas was being used by Palestinian militants to provoke an uprising, spread panic. He found that Arab medical personnel, in turn, decided that the "poison" must be coming from the Israeli side.Baruch Modan, director general of Israel's health ministry, also concluded that most of the victims of the epidemic suffered from a psychological malady, though he said that some who fell ill after April 3 were faking, when epidemiologists say that the outbreak had subsided. Hefez wrote in his 1985 study "The Role of the Press and the Medical Community in the epidemic of 'Mysterious Gas Poisoning' in the Jordan West Bank" that Israeli newspaper reports of poisoning at the start of the epidemic added fuel to the flames. A front-page article in Ha'aretz on March 28, 1983 even claimed that Israeli military investigators had found traces of nerve gas and quoted "army sources" as saying that they suspected that Palestinian militants were poisoning their own people in order to blame Israel and provoke an uprising. Palestinian leaders followed up with accusations that Israel had poisoned them in an attempt to drive them from the West Bank.

Such epidemic hysteria has a long history. Notable cases are the Salem witch trials, the Tanganyika laughter epidemic of 1962, and the 2008–2012 outbreak of psychogenic illness among Afghan school girls over suspected Taliban poisoning.